Cannabinoids, as their name suggests, are bioactive compounds typically found within cannabis. Interestingly, however, several cannabinoids have been detected in a wide range of other plants, endowing these species with healing and psychoactive properties.
What Is A Cannabinoid?
Before we talk about which plants contain cannabinoids, we need to clear up some of the confusion surrounding what actually qualifies as a cannabinoid in the first place. Originally, the term was used to describe a class of terpenoids that were believed to be exclusive to cannabis – although many have since been identified in other plants.
After the discovery of cannabinoid receptors in the central nervous system, however, the definition was adapted to refer to anything that acts upon these receptors. This includes phytocannabinoids like THC as well as endocannabinoids (meaning the body’s own cannabinoids) such as anandamide.
To be really specific, cannabinoids are molecules that consist of a resorcinyl core, an isoprenyl residue and a side chain, although the term is often applied to compounds that lack this chemical structure. For instance, many plants contain cannabimimetics, which are not true cannabinoids but do interfere with the endocannabinoid system, and are therefore sometimes referred to as cannabinoids.
While commercial chocolate doesn’t contain any cannabinoids, raw cocoa is a source of anandamide. Drawing its name from the Sanskrit word for bliss, anandamide occurs naturally within the human body and binds to the CB1 receptor, just as THC does. In doing so, it generates feelings of euphoria.
As a double whammy, cocoa also contains a range of molecules called N-acylethanolamines (NAEs), which prolong the effects of anandamide by inhibiting FAAH, the enzyme that breaks down this endocannabinoid. Because of this, it’s sometimes said that consuming raw cocoa enhances the effects of cannabis.
While this has not been scientifically confirmed, we’d definitely volunteer to participate in any clinical trial to find out!
Several varieties of rhododendron contain cannabinoids or cannabinoid derivatives. For example, the species Rhododendron anthopogonoides is found throughout southern China and has long been used as a remedy for bronchitis. The plant contains several compounds that are analogues of the cannabinoid cannabichromeme (CBC), such as confluentin[i].
Interestingly, confluentin is the only cannabinoid-like molecule that has ever been obtained from a source that is neither plant or animal, having been identified in a type of rot that attacks nematodes[ii].
Obviously, we wouldn’t recommend smoking a mouldy nematode, but it’s cool to know that plant cannabinoids can be found in some unexpected places!
Though generally considered a terpene, beta-caryophyllene has also been found to bind to the CB2 receptor, with studies showing that it has anti-inflammatory and painkilling effects[iii]. As such, it really does tick all the boxes and has fully earned the title of cannabinoid.
Beta-caryophyllene is also found in black pepper, which will come as no surprise to cannabis connoisseurs who have noticed the peppery flavour of certain cultivars.
Though lacking in genuine cannabinoids, echinacea is loaded with cannabimimetic compounds that directly impact the endocannabinoid system without binding to its receptors. Specifically, it contains a class of molecules known as N-alkylamides, some of which inhibit FAAH and therefore prevent the breakdown of anandamide.
It’s thought this regulation of the endocannabinoid system plays a major role in the anti-inflammatory and anti-anxiety properties of echinacea.
Woolly Umbrella Helichrysum (helichrysum umbraculigerum)
This one may seem a little obscure, especially to anyone outside of South Africa, where this daisy-like flower grows. Yet the plant is considered a rich source of cannabinoids, particularly cannabigerol (CBG).
Sometimes used as an anti-depressant and in ritual ceremonies, the plant is said to have psychoactive properties that resemble those of cannabis itself. Interestingly, however, a recent study found that the CBG-derivatives in woolly umbrella helichrysum have a lower binding affinity for cannabinoid receptors than CBG obtained from cannabis[iv].
[i] Gülck T, Møller BL. Phytocannabinoids: origins and biosynthesis. Trends in Plant Science. 2020 Jul 6. – https://www.sciencedirect.com/science/article/pii/S1360138520301874
[ii] Quaghebeur K, Coosemans J, Toppet S, Compernolle F. Cannabiorci-and 8-chlorocannabiorcichromenic acid as fungal antagonists from Cylindrocarpon olidum. Phytochemistry. 1994 Sep 1;37(1):159-61. – https://pubmed.ncbi.nlm.nih.gov/7765609/
[iii] Gertsch J, Pertwee RG, Di Marzo V. Phytocannabinoids beyond the Cannabis plant–do they exist?. British journal of pharmacology. 2010 Jun;160(3):523-9. – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931553/
[iv] Pollastro F, De Petrocellis L, Schiano-Moriello A, Chianese G, Heyman H, Appendino G, Taglialatela-Scafati O. Amorfrutin-type phytocannabinoids from Helichrysum umbraculigerum. Fitoterapia. 2017 Nov 1;123:13-7. – https://www.sciencedirect.com/science/article/abs/pii/S0367326X17311620